keyctl_describe_key() turns the key reference it gets into a usable key pointerand assigns that to a variable called 'key', which it then ignores in favour ofrecomputing the key pointer each time it needs it. Make it use the precomputedpointer instead.

Without this patch, gcc 4.6 reports that the variable key is set but not used:

building with gcc 4.6 I'm getting a warning message: CC security/keys/keyctl.o security/keys/keyctl.c: In function 'keyctl_describe_key': security/keys/keyctl.c:472:14: warning: variable 'key' set but not used